Some time ago I had the idea to build a Beast Master Ranger who has a miniature gelatinous cube for her "animal" companion. I set about creating the stats for this cube. If everything is ignored, which has to do with the DM that allows this (a separate discussion), is this creature balanced for the companion of a ranger?
AC 10 HP 28
str: 14 Dex: 7 con: 14 Int: 1 Wis: 6 Cha: 10
speed: 30 ft.
senses: Blindsight 60 ft.
Conditions immunities and Trains: Same as the Gelatinous Cube (Ooze Cube, Transparent). The acid damage of Ooze Cube has been reduced to 3d4.
size: Small, 3 x 3 ft. Cube.
Pseudopod +4 hit, 5ft range, 3d4 acid damage.
Devour. Like normal cubes except for 3d4 initial acid damage, 6d4 when moving from G.Noob and only small or smaller creatures.
I've tried to correlate the statistics with other animals (especially the monkey, the black bear, the giant owl, the panther, the horseman, and the swarm of insects (not an animal mate, but a 1/2 CR thing near a GC) the feeling of a gelatinous cube.
Is this creature balanced in terms of survivability, damage output, and overall combat effectiveness for an R 1/4 animal lover as a ranger? If not, how can I change it to be balanced?